Recommendations for the selection and treatment of patients with idiopathic intracranial hypertension for venous sinus stenting

Differentiation Between the Low and High Trans-Stenotic Pressure Gradient in Patients With Idiopathic Intracranial Hypertension Using 4D Flow MRI-Derived Hemodynamic Parameters

BACKGROUND

Trans-stenotic pressure gradient (TPG) measurement is essential for idiopathic intracranial hypertension (IIH) patients with transverse sinus (TS) stenosis. Four-D flow MRI may provide a noninvasive imaging method for differentiation of IIH patients with different TPG.

PURPOSE

To investigate the associations between 4D flow parameters and TPG, and to evaluate the diagnostic performance of 4D flow parameters in differentiating patients with high TPG (GroupHP) from low TPG (GroupLP).

STUDY TYPE

Prospective.

POPULATION

31 IIH patients with TS stenosis (age, 38 ± 12 years; 23 females) and 5 healthy volunteers (age, 25 ± 1 years; 2 females).

FIELD STRENGTH/SEQUENCE

3T, 3D phase contrast MR venography, and gradient recalled echo 4D flow sequences.

ASSESSMENT

Scan-rescan reproducibility of 4D flow parameters were performed. The correlation between TPG and flow parameters was analyzed. The netflow and velocity difference between inflow plane, outflow plane, and the stenosis plane were calculated and compared between GroupHP and GroupLP.

STATISTICAL TESTS

Pearson's correlation or Spearman's rank correlation coefficient, Independent samples t-test or Wilcoxon rank-sum test, Intra-class correlation coefficient (ICC), Bland-Altman analyses, Receiver operating characteristic curves. A P value <0.05 was considered significant.

RESULTS

Significant correlations were found between TPG and netflow parameters including Favg,out-s, Favg,in-s, Fmax,out-s, and Fmax,in-s (r = 0.525-0.565). Significant differences were found in Favg,out-s, Fmax,out-s, Favg,in-s, and Fmax,in-s between GroupHP and GroupLP. Using the cut-off value of 2.19 mL/sec, the Favg,out-s showed good estimate performance in distinguishing GroupHP from GroupLP (AUC = 0.856). The ICC (ranged 0.905-0.948) and Bland-Altman plots indicated good scan-rescan reproducibility.

DATA CONCLUSIONS

4D flow MRI derived flow parameters showed good correlations with TPG in IIH patients with TS stenosis. Netflow difference between outflow and stenosis location at TS shows the good performance in differentiating GroupHP and GroupLP cases.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

Future Directions and Innovations in Venous Sinus Stenting

This review explores the future role of venous sinus stenting (VSS) in the management of idiopathic intracranial hypertension and pulsatile tinnitus. Despite its favorable safety profile and clinical outcomes compared with traditional treatments, VSS is not yet the standard of care for these conditions, lacking high-level evidence data and guidelines for patient selection and indications. Current and recently completed clinical trials are expected to provide data to support the adoption of VSS as a primary treatment option. Additionally, VSS shows potential in treating other conditions, such as dural arteriovenous fistula and cerebral venous sinus thrombosis, and it is likely that the procedure will continue to see an expansion of its approved indications. The current lack of dedicated venous stenting technology is being addressed with promising advancements, which may improve procedural ease and patient outcomes. VSS also offers potential for expansion into modulation of brain electrophysiology via endovascular routes, offering exciting possibilities for neurodiagnostics and treatment of neurodegenerative disorders.

Challenges in the use of Venous Sinus Stenting in the Treatment of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Although numerous case series and meta-analyses have shown the efficacy of venous sinus stenting (VSS) in the treatment of idiopathic intracranial hypertension and idiopathic intracranial hypertension-associated pulsatile tinnitus, there remain numerous challenges to be resolved. There is no widespread agreement on candidacy; pressure gradient and failed medical treatment are common indications, but not all clinicians require medical refractoriness as a criterion. Venous manometry, venography, and cerebral angiography are essential tools for patient assessment, but again disagreements exist regarding the best, or most appropriate, diagnostic imaging choice. Challenges with the VSS technique also exist, such as stent choice and deployment. There are considerations regarding postprocedural balloon angioplasty and pharmacologic treatment, but there is insufficient evidence to formalize postoperative decision making. Although complications of VSS are relatively rare, they include in-stent stenosis, hemorrhage, and subdural hematoma, and the learning curve for VSS presents specific challenges in navigating venous anatomy, emphasizing the need for wider availability of high-quality training. Recurrence of symptoms, particularly stent-adjacent stenosis, poses challenges, and although restenting and cerebrospinal fluid-diverting procedures are options, there is a need for clearer criteria for retreatment strategies. Despite these challenges, when comparing VSS with traditional cerebrospinal fluid-diverting procedures, VSS emerges as a favorable option, with strong clinical outcomes, lower complication rates, and cost-effectiveness. Further research is necessary to refine techniques and indications and address specific aspects of VSS to overcome these challenges.

Prediction of Venous Trans-Stenotic Pressure Gradient Using Shape Features Derived From Magnetic Resonance Venography in Idiopathic Intracranial Hypertension Patients

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology associated with venous sinus stenosis. This study aimed to develop a magnetic resonance venography (MRV)-based radiomics model for predicting a high trans-stenotic pressure gradient (TPG) in IIH patients diagnosed with venous sinus stenosis.

MATERIALS AND METHODS

This retrospective study included 105 IIH patients (median age [interquartile range], 35 years [27-42 years]; female:male, 82:23) who underwent MRV and catheter venography complemented by venous manometry. Contrast enhanced-MRV was conducted under 1.5 Tesla system, and the images were reconstructed using a standard algorithm. Shape features were derived from MRV images via the PyRadiomics package and selected by utilizing the least absolute shrinkage and selection operator (LASSO) method. A radiomics score for predicting high TPG (≥ 8 mmHg) in IIH patients was formulated using multivariable logistic regression; its discrimination performance was assessed using the area under the receiver operating characteristic curve (AUROC). A nomogram was constructed by incorporating the radiomics scores and clinical features.

RESULTS

Data from 105 patients were randomly divided into two distinct datasets for model training (n = 73; 50 and 23 with and without high TPG, respectively) and testing (n = 32; 22 and 10 with and without high TPG, respectively). Three informative shape features were identified in the training datasets: least axis length, sphericity, and maximum three-dimensional diameter. The radiomics score for predicting high TPG in IIH patients demonstrated an AUROC of 0.906 (95% confidence interval, 0.836-0.976) in the training dataset and 0.877 (95% confidence interval, 0.755-0.999) in the test dataset. The nomogram showed good calibration.

CONCLUSION

Our study presents the feasibility of a novel model for predicting high TPG in IIH patients using radiomics analysis of noninvasive MRV-based shape features. This information may aid clinicians in identifying patients who may benefit from stenting.

Zilver stent versus Carotid Wallstent for endovascular treatment of idiopathic intracranial hypertension

BACKGROUND

Venous sinus stenting (VSS) is a promising treatment option for medically refractory idiopathic intracranial hypertension (IIH). There are no published studies comparing the performance of different types of stents employed in VSS procedures. In this study we aimed to compare the safety and efficacy outcomes of the Zilver 518 (Cook Medical, Bloomington, Indiana, USA) and the Carotid Wallstent (Boston Scientific, Marlborough, Massachusetts, USA) devices.

METHODS

Records of patients with IIH who underwent VSS between January 2015 and February 2022 at a single referral center were retrospectively reviewed. Patients treated with the Zilver stent or Carotid Wallstent were included in the study. Stent model and size data, pre- and post-treatment pressure gradients, technical and safety outcomes, and pre- and post- stenting papilledema, headache, and tinnitus severity were collected. The χ2 and Fisher-Freeman-Halton tests were used for categorical data and the Student's t-test and Mann-Whitney U test were employed to examine the differences in non-categorical variables.

RESULTS

A total of 81 procedures (28 (34.5%) with the Zilver stent and 53 (65.5%) with the Carotid Wallstent) were performed in 76 patients. The mean procedure time was significantly shorter with the Zilver stent (22.56±10.2 vs 33.9±15 min, p=0.001). The papilledema improvement and resolution rates did not significantly differ between groups (94.7% vs 94.5%, p>0.99 for improvement; 78.9% vs 67.5%, p=0.37 for resolution). The tinnitus improvement and resolution rates in the Zilver stent group were significantly higher than those of the Carotid Wallstent group (100% vs 78.9%, p=0.041; 90% vs 63.1%, p=0.03, respectively). Additionally, the Zilver stent provided a significantly higher rate of headache resolution and improvement than the Carotid Wallstent (84.6% vs 27.6%, p=0.001 for resolution; 92.3% vs 72.3%, p=0.043 for improvement). One patient from the Carotid Wallstent group underwent re-stenting due to in-stent stenosis and refractory papilledema. No significant in-stent stenosis was observed in the Zilver stent group.

CONCLUSION

Stent choice may affect VSS outcomes. The Zilver stent provided better clinical outcomes than the Carotid Wallstent, with significantly shorter procedure times. Larger studies are needed to determine the efficacy of available venous stents for IIH.

Cerebral venous disorders: Diagnosis and endovascular management

The role of the venous circulation in neurological diseases has been underestimated. In this review, we present an overview of the intracranial venous anatomy, venous disorders of the central nervous system, and options for endovascular management. We discuss the role the venous circulation plays in various neurological diseases including cerebrospinal fluid (CSF) disorders (intracranial hypertension and intracranial hypotension), arteriovenous diseases, and pulsatile tinnitus. We also shed light on emergent cerebral venous interventions including transvenous brain-computer interface implantation, transvenous treatment of communicating hydrocephalus, and the endovascular treatment of CSF-venous disorders.

A new method for assessing transverse sinus stenosis with CT venography based on the venous trans-stenotic pressure gradient

BACKGROUND

Evaluation of the transverse sinus stenosis (TSS) is essential for TSS-related diseases.

OBJECTIVE

To investigate a new method for the quantitative assessment of TSS based on the correlation between TSS and trans-stenotic pressure gradient (TPG).

METHODS

Patients with unilateral pulsatile tinnitus with or without idiopathic intracranial hypertension were retrospectively included. All patients underwent CT venography and venous manometry and were confirmed to have TSS. The cross-sectional diameter/area of TSS, the poststenotic and prestenotic segments, and the superior sagittal sinus (SSS) were measured. The degree of TSS was calculated by dividing the diameter/area of TSS by the diameter/area of the poststenotic segment (M1/M2), prestenotic segment (M3/M4), and SSS (M5/M6). Partial correlation analysis (controlling for the effect of age, sex, outflow laterality, and contralateral stenosis) was performed to evaluate the correlation between M1-M6 and the TPG. Receiver operating characteristic curve analysis of M1-M6 for diagnosing a significant TPG (≥8 mm Hg) was performed.

RESULTS

Ninety-nine patients met the inclusion criteria. The partial correlation coefficients between M1-M6 and the TPG were 0.60, 0.61, 0.43, 0.48, 0.39, and 0.54, respectively. The areas under the curve (AUCs) of M1-M6 for diagnosing a significant TPG were 0.81, 0.86, 0.68, 0.69, 0.64, and 0.72, respectively. The AUC of M2 was significantly larger than that of M3 (P=0.002), M4 (P<0.001), M5 (P=0.001), and M6 (P<0.001).

CONCLUSIONS

Quantitatively assessing TSS by taking the ratio of the cross-sectional area of TSS to that of the poststenotic segment might be a more efficient method for predicting the TPG.

A descriptive study of venous pressures and gradients while awake and both pre- and post-stent under anesthesia in patients with idiopathic intracranial hypertension

BACKGROUND

This study aims to explore factors that affect venous sinus pressures and associated gradients while awake and under general anesthesia (GA) both before and after venous sinus stenting (VSS) in patients with idiopathic intracranial hypertension (IIH).

METHODS

A retrospective analysis was performed examining pressures and gradients in patients with IIH having undergone awake venography followed by VSS under GA.

RESULTS

174 patients were included. Compared with awake, GA superior sagittal sinus (SSS) pressures were 2.6 mmHg lower (p=0.01) resulting in a total cranial gradient reduction of 2.5 mmHg (p=0.002). The transverse-sigmoid gradient, the most commonly stented segment, did not differ under the two conditions (p=0.30). Regression analyses demonstrated that body mass index, gender, blood pressure, and end-tidal carbon dioxide content significantly affected venous pressures (all p<0.05). After stenting, mean total cranial gradients decreased by 13.2 mmHg while skull base gradients increased by 0.8 mmHg. Stenting resulted in an 84% mean reduction in the target gradient and a mean decrease in SSS pressures by 78% of the target gradient. When cardiopulmonary and anesthetic factors were optimized, GA had a limited effect on the target gradient in most patients (p=0.88).

CONCLUSIONS

This study is the largest series to date to report on cerebral venous pressure measurements and gradients recorded while awake and under GA both before and after VSS for IIH. In a well-controlled cardiorespiratory and anesthetic setting, GA venography may provide information that is not substantially inequivalent to that obtained while awake.

Blood Flow Velocity: a Decision Tool for Stenting Indication in Venous Pulsatile Tinnitus

BACKGROUND AND PURPOSE

Lateral sinus stenosis is the most common cause of venous pulsatile tinnitus (VPT). Stenting is an effective treatment after demonstration of a trans-stenotic pressure gradient; however, pressure measurement has many technical limitations. In 2018, a study showed that a combined approach with intravascular velocity measurement could be effective in identifying most appropriate candidates for stenting. The aim of the present study was to evaluate a new strategy using this biomarker for the indication of stenting even without a significant pressure gradient.

MATERIAL AND METHODS

Consecutive patients with disabling VPT were included from 2016 to 2019 and analyzed retrospectively. Intrasinusal pressures were measured and blood flow velocities (with a dual-sensor guidewire) were used for the indication of stenting independent of the pressure gradient. We evaluated the clinical outcome after stenting based on this new biomarker.

RESULTS

A total of 41 patients were treated according to this strategy. At last follow-up (mean = 30.2 months), 32/33 patients (97%) treated by stenting showed complete resolution or a significant decrease in VPT intensity. The use of velocity as the threshold for indicating stenting identified 8 patients (24%) missed by the pressure gradient. Their clinical outcome after stenting was excellent and no complications occurred.

CONCLUSION

Measurement of sinus blood flow velocity provides a hemodynamic explanation of disease and may be a better tool than pressure gradient for the indication of stenting in VPT.

Long-term safety and efficacy of stenting on correcting internal jugular vein and cerebral venous sinus stenosis

OBJECTIVES

To compare the long-term safety and efficacy of stenting in correcting cerebral venous sinus stenosis (CVSS) and internal jugular venous stenosis (IJVS).

METHODS

Patients confirmed with CVSS or IJVS by imaging were enrolled in this real-world study from 2014 through 2021. Clinical characteristics and long-term outcomes of these two diseases entities post-stenting were followed up and compared.

RESULTS

Three hundred and nineteen patients were enrolled in this study, with a mean age of 48.83 years and a BMI of 25.08 on average. In which, 144 patients underwent stenting, the stenotic segments were corrected and the venous blood flow was restored immediately post-stenting. At 6.15 ± 1.67 days follow-up, significant improvement was observed in headache, tinnitus, insomnia, ICP, and mean pressure gradient in both groups (all p < 0.05). At 30.53 ± 4.41 months follow-up post-stenting, the headache, tinnitus, visual loss, papilledema, and insomnia were attenuated remarkably or even completely disappeared. The Frisen papilledema grade scores declined from 2 (0-4) to 1 (0-3) in IJVS group and from 4 (1-5) to 1 (0-4) in CVSS group compared to the baseline. One hundred and twenty-seven out of the 144 patients (95.5%) maintained sufficient blood flow verified by followed up computed tomographic venography or contrast-enhanced magnetic resonance angiography. Adverse events related to stenting included three cases of intraluminal restenosis and three cases of in-stent thrombosis, no intracranial hemorrhage, venous thromboembolisms, stent-adjacent stenosis, and stent displacement occurred.

INTERPRETATION

Using stents to correct IH and related neurological issues has shown to be a safe and effective approach for both IJVS and CVSS.

Combined surgical repair and venous sinus stenting for patients with skull base encephaloceles secondary to dural venous sinus stenosis

BACKGROUND

Chronically elevated intracranial pressure (ICP) seen in idiopathic intracranial hypertension (IIH) can cause the development of skull base encephaloceles and cerebrospinal fluid (CSF) leaks. Surgical repair and ventriculoperitoneal shunt (VPS) placement are mainstays of treatment. Venous sinus stenting (VSS) is a newly accepted treatment modality. The goal of this study was thus to determine if VSS can be used to treat symptoms and prevent recurrence after surgical encephalocele repair.

METHODS

Retrospective chart review of patients that had surgical repair of encephaloceles followed by VSS for symptomatic stenosis with elevated pressure gradient.

RESULTS

A total of 13 patients underwent a combined encephalocele repair and VSS. Seventy-two percent were female; 46% had headaches, 69% pulsatile tinnitus, and 92% CSF rhinorrhea or otorrhea. One had seizures. Mean lumbar opening pressure was 23.3 ± 2.6 cm H2O; the average sagittal-to-jugular pressure gradient was 12.7 ± 1.8 cmH2O and was elevated in all patients. Four patients had middle fossa craniotomy for repair of tegmen defect (one bilateral); one had a retrosigmoid craniotomy for repair of a sigmoid plate defect. Eight had an endoscopic endonasal repair for sphenoid or cribriform plate encephalocele. There were no VSS procedural complications or complications associated with dual antiplatelet therapy. One patient had meningitis after endoscopic repair that was treated with antibiotics. One patient had recurrence of both CSF leak and venous stenosis adjacent to the stent requiring repeat repair and VSS. There was no further recurrence.

CONCLUSION

In patients with dural sinus stenosis and encephaloceles requiring repair, VSS can be performed safely within weeks of surgery for relief of symptoms, resolution of underlying pathology, and prevention of CSF leak recurrence.

"Idiopathic" intracranial hypertension: An update from neurointerventional research for clinicians

BACKGROUND

The recognition of venous sinus stenosis as a contributing factor in the majority of patients with idiopathic intracranial hypertension coupled with increasing cerebral venography and venous sinus stenting experience have dramatically improved our understanding of the pathophysiologic mechanisms driving this disease. There is now a dense, growing body of research in the neurointerventional literature detailing anatomical and physiological mechanisms of disease which has not been widely disseminated among clinicians.

METHODS

A literature search was conducted, covering the most recent neurointerventional literature on idiopathic intracranial hypertension, the pathophysiology of idiopathic intracranial hypertension, and management strategies (including venous sinus stenting), and subsequently summarized to provide a comprehensive review of the most recently published studies on idiopathic intracranial hypertension pathophysiology and management.

CONCLUSION

Recent studies in the neurointerventional literature have greatly improved our understanding of the pathophysiologic mechanisms causing idiopathic intracranial hypertension and its associated conditions. The ability to make individualized, patient-specific treatment approaches has been made possible by advances in our understanding of how venous sinus stenosis and cerebral venous hypertension fundamentally contribute to idiopathic intracranial hypertension.

Estimation of venous sinus pressure drop in patients with idiopathic intracranial hypertension using 4D-flow MRI

OBJECTIVE

We aimed to explore a non-invasive estimate of pressure drop in patients who undergo venous sinus stenting to treat idiopathic intracranial hypertension (IIH).

METHODS

This prospective study included 28 IIH patients scheduled for venous stenting. 4D-flow MRI was acquired 24-48 h before venous manometry. Manometry-obtained pressure drop (Mp) was dichotomized into low (Lp: 0-8 mmHg) and high (Hp: 8-30 mmHg) groups. Hemodynamic indices were compared between Lp and Hp. Trans-stenotic pressure drop was estimated by work-energy equation, simplified Bernoulli equation, vorticity magnitude, and velocity difference between inlet and outlet and was compared with Mp. Measurement agreement, correlation, and accuracy were evaluated using the κ coefficient, Pearson's r, and confusion matrix-derived accuracy.

RESULTS

Among 28 patients (mean age 38.8 ± 12.7), 19 (67.9%) were female. Work-energy equation-estimated pressure drop (WEp) had strong correlation (r = 0.91, 95% confidence interval [CI]: 0.81-0.96, p < 0.001) and high agreement (intraclass correlation coefficient = 0.90, 95% CI: 0.78-0.95, p < 0.001) with Mp. WEp classified Lp and Hp with an accuracy of 0.96. The κ value between WEp and Mp was 0.92 (95% CI: 0.78-1.00). In the work-energy equation, the viscosity energy term (V_e) had the largest weights, and the ratio of V_e to the summation of the three energy terms was 0.93 ± 0.07. V_e had strong correlation with mVort (r = 0.93, 95% CI: 0.85-0.97, p < 0.001), and mean vorticity magnitude was significantly elevated in Hp compared to that in Lp (259.8 vs. 174.9 mL/s, p < 0.001).

CONCLUSION

Trans-stenotic pressure drop in IIH can be estimated using the work-energy equation with favorable accuracy.

KEY POINTS

• Trans-stenotic pressure drop in patients with idiopathic intracranial hypertension can be estimated accurately with the work-energy equation using the 4D-flow MRI full velocity field. • Compared with traditional venous sinus manometry, the 4D-flow MRI-derived pressure drop is totally non-invasive and cost-saving. • 4D-flow MRI may help neurointerventionalist to select IIH patients suitable for venous sinus stenting.

Technical and clinical success after venous sinus stenting for treatment of idiopathic intracranial hypertension using a novel guide catheter for access: Case series and initial multi-center experience

INTRODUCTION

Venous sinus stenting is a well established alternative to cerebrospinal fluid diversion for the treatment of idiopathic intracranial hypertension (IIH) with associated venous sinus stenosis. During this procedure, distal guide catheter placement within the venous sinuses may be desirable to facilitate stent delivery. We report our initial experience using the TracStar LDP™ (Imperative Care, Campbell, USA, 0.088-inch inner diameter) as the guide catheter for intracranial access during venous sinus stenting.

METHODS

A multi-institutional retrospective chart review of a prospectively maintained IRB-approved database was performed. Consecutive patients who underwent venous sinus stenting from 1/1/2020-9/6/2021 for IIH were included. Patient characteristics, procedural details, TracStar distal reach, outcomes, and complications were collected and analyzed.

RESULTS

Fifty-eight patients were included. The mean age was 33.8 years and 93.1% of patients were female. Visual changes prompted evaluation in 86.2% of patients. Stent placement was successful in all patients. The TracStar LDP catheter was advanced to the location of stent placement in 97.9% of cases in which it was attempted. The large 0.088-inch inner diameter lumen enabled compatibility with all desired stent sizes ranging from six to 10 millimeters. Gradient pressure across transverse sinus stenosis dropped from an average of 19.5 mmHg pre-procedure to 1.7 mmHg post-stent placement (p < 0.001). Clinical improvement was achieved in 87.9% (51/58) of patients. There were no catheter-related complications.

CONCLUSION

The TracStar LDP is a safe and effective access platform for reaching treatment locations in patients who present with idiopathic intracranial hypertension and who are candidates for venous sinus stent placement.

Venous Sinus Stenting for Low Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension

BACKGROUND

Medically refractory idiopathic intracranial hypertension (IIH) is frequently treated with venous sinus stenosis stenting with high success rates. Patient selection has been driven almost exclusively by identification of supraphysiological venous pressure gradients across stenotic regions based on theoretical assessment of likelihood of response.

OBJECTIVE

To explore the possibility of benefit in low venous pressure gradient patients.

METHODS

Using a single-center, prospectively maintained registry of patients with IIH undergoing venous stenting, we defined treatment groups by gradient pressures of ≤4, 5 to 8, and >8 mmHg based on the most frequently previously published thresholds for stenting. Baseline demographics, clinical, and neuro-ophthalmological outcomes (including optical coherence tomography and Humphrey visual fields) were compared.

RESULTS

Among 53 patients, the mean age was 32 years and 70% female with a mean body mass index was 36 kg/m 2 . Baseline characteristics were similar between groups. The mean change in lumbar puncture opening pressure at 6 months poststenting was similar between the 3 groups (≤4, 5-8, and >8 mmHg; 13.4, 12.9, and 12.4 cmH 2 O, P = .47). Papilledema improvement was observed across groups at 6 months (100, 93, and 86, P = .7) as were all clinical symptoms. The mean changes in optical coherence tomography retinal nerve fiber layer (-30, -54, and -104, P = .5) and mean deviation in Humphrey visual fields (60, 64, and 67, P = .5) at 6 weeks were not significantly different.

CONCLUSION

Patients with IH with low venous pressure gradient venous sinus stenosis seem to benefit equally from venous stenting compared with their higher gradient counterparts. Re-evaluation of our restrictive criteria for this potentially vision sparing intervention is warranted. Future prospective confirmatory studies are needed.

Intra-procedural cerebral sinus thrombosis during endovascular treatment of idiopathic intracranial hypertension

Stenting of the intracranial venous sinuses has shown promising results in patients who are refractory to medical treatment of idiopathic intracranial hypertension (IIH). Among the reported complications associated with this procedure, in-stent thrombosis is an unreported one. We present a case of cerebral sinus thrombosis during endovascular treatment of IIH. A 33-year-old man with multiple comorbidities was presented with non-specific vision changes and headaches. Initial workup revealed a diagnosis of idiopathic intracranial hypertension which was treated medically but with no improvement. Therefore, cerebral sinus stenting was pursued. During the procedure, an in-stent thrombus was identified which was retrieved mechanically and was sent for histological and immunohistochemical evaluation. The retrieved thrombus was predominantly composed of RBCs (57.8%) followed by fibrin (30.78%), platelet (6.4%), and WBCs (5.95%), with high expression of CitH3 (neutrophil extra cellular traps specific marker) (10.9%), and CD66 (11.35%).

Case Report of Idiopathic Intracranial Hypertension in Pregnancy

Idiopathic intracranial hypertension (IIH) is a disease of increased intracranial pressure with an unknown cause that is seen most often in women during their childbearing years. Women can be under care for IIH when they become pregnant, or it may occur during pregnancy. In the past, women with IIH who became pregnant were often counseled to terminate their pregnancies, to give birth early, and even to be sterilized to prevent future pregnancies. Today, multiple therapeutic options are available. In this case report, I describe the case of a woman with IIH who was treated with a cerebral spinal fluid shunt and gave birth to two sets of twins. This case report adds new information to the limited nursing literature currently available on this disease.

Idiopathic intracranial hypertension imaging approaches and the implications in patient management

Idiopathic intracranial hypertension (IIH) represents a clinical disease entity without a clear etiology, that if left untreated, can result in severe outcomes, including permanent vision loss. For this reason, early diagnosis and treatment is necessary. Historically, the role of cross-sectional imaging has been to rule out secondary or emergent causes of increased intracranial pressure, including tumor, infection, hydrocephalus, or venous thrombosis. MRI and MRV, however, can serve as valuable imaging tools to not only rule out causes for secondary intracranial hypertension but can also detect indirect signs of IIH resultant from increased intracranial pressure, and demonstrate potentially treatable sinus venous stenosis. Digital subtraction venographic imaging also plays a central role in both diagnosis and treatment, providing enhanced anatomic delineation and temporal flow evaluation, quantitative assessment of the pressure gradient across a venous stenosis, treatment guidance, and immediate opportunity for endovascular therapy. In this review, we discuss the multiple modalities for imaging IIH, their limitations, and their contributions to the management of IIH.

Prediction of the trans-stenotic pressure gradient with arteriography-derived hemodynamic features in patients with idiopathic intracranial hypertension

The pathogenesis of idiopathic intracranial hypertension (IIH) is attributed to segmental stenosis of the venous sinus. The current treatment paradigm requires a trans-stenotic pressure gradient of ≥8 mmHg or ≥6 mmHg threshold. This study aimed to develop a machine learning screening method to identify patients with IIH using hemodynamic features. A total of 204 venous manometry instances (n = 142, training and validation; n = 62, test) from 135 patients were included. Radiomic features extracted from five arteriography perfusion parameter maps were selected using least absolute shrinkage and selection operator and then entered into support vector machine (SVM) classifiers. The Thr8-23-SVM classifier was created with 23 radiomic features to predict if the pressure gradient was ≥8 mmHg. On an independent test dataset, prediction sensitivity, specificity, accuracy, and AUC were 0.972, 0.846, 0.919, and 0.980, respectively (95% confidence interval: 0.980-1.000). For the 6 mmHg threshold, thr6-28-SVM incorporated 28 features, and its sensitivity, specificity, accuracy, and AUC were 0.923, 0.956, 0.935, and 0.969, respectively (95% confidence interval: 0.927-1.000). The trans-stenotic pressure gradient result was associated with perfusion pattern changes, and SVM classifiers trained with arteriography perfusion map-derived radiomic features could predict the 8 mmHg and 6 mmHg dichotomized trans-stenotic pressure gradients with favorable accuracy.

Cerebral Venous Outflow Implications in Idiopathic Intracranial Hypertension-From Physiopathology to Treatment

In this review, we provide an update on the pathogenesis, diagnosis, and management of adults with idiopathic intracranial hypertension (IIH) and implications of the cerebral venous system, highlighting the progress made during the past decade with regard to mechanisms of the venous outflow pathway and its connection with the cerebral glymphatic and lymphatic network in genesis of IIH. Early diagnosis and treatment are crucial for favorable visual outcomes and to avoid vision loss, but there is also a risk of overdiagnosis and misdiagnosis in many patients with IIH. We also present details about treatment of intracranial hypertension, which is possible in most cases with a combination of weight loss and drug treatments, but also in selected cases with surgical interventions such as optic nerve sheath fenestration, cerebral spinal fluid (CSF) diversion, or dural venous sinus stenting for some patients with cerebral venous sinus stenosis, after careful analysis of mechanisms of intracranial hypertension, patient clinical profile, and method risks.

Safety and efficacy comparison between OACs plus single antiplatelet and dual antiplatelet therapy in patients with cerebral venous sinus stenosis poststenting

Background and purpose

The present strategies regarding poststent management for cerebral venous sinus stenosis (CVSS) are inconsistent. Herein, we compared the safety and efficacy of oral anticoagulants (OACs) plus single antiplatelet therapy and dual antiplatelet therapy for CVSS poststenting.

Methods

A real-world observational study conducted from January 2009 through October 2019 enrolled patients who were diagnosed with CVSS and received stenting. Patients were divided into two groups according to the management they received poststenting. Group 1: OACs plus a single antiplatelet agent (clopidogrel 75 mg or aspirin 100 mg) and Group 2: dual antiplatelet therapy (clopidogrel 75 mg plus aspirin 100 mg). The safety (such as major or minor bleeding or venous thrombosis) and efficacy (the incidences of cerebral venous sinus restenosis, intrastent thrombosis, or stent displacement) of the two groups were compared.

Results

There were a total of 110 eligible patients in the final analysis, including 79 females and 31 males with a mean age of 43.42 ± 13.23 years. No major bleeding or venous thrombosis occurred in either of the two groups. Two minor bleeding events occurred in group 2 (one with subcutaneous bleeding points in both lower limbs, another with submucosal bleeding in the mouth), whereas no bleeding events occurred in Group 1. In addition, at the 1-year follow-up, one case of intraluminal restenosis and two cases of in-stent thrombi occurred in Group 2, while none occurred in Group 1. Neither stenosis at stent-adjacent segments nor stent migration was detected in either group during the 1-year following stent placement.

Conclusion

OACs plus single antiplatelet therapy and dual antiplatelet therapy alone are both safe and efficacious management strategies after CVSS stent placement. The former may have more advantages than the latter for inhibiting intrastent thrombosis. However, further research by larger, multicenter clinical trials is needed.

Update on Idiopathic Intracranial Hypertension Management

BACKGROUND

Idiopathic Intracranial Hypertension (IIH) is a secondary headache with a steadily growing incidence. Currently, there is little evidence to guide the treatment of IIH.

OBJECTIVE

To review the pathophysiology of IIH, with focus on the role of obesity as a risk factor, and the implications for new therapeutic perspectives.

METHODS

in this narrative review, we summarized the current knowledge on treatment options highlighting available evidence for managing intracranial hypertension, obesity, and headache.

RESULTS

Clinical Presentation: headache is the most common symptom and a significant cause of quality-of-life impairment. Visual loss is common in the diagnosis. Pathophysiology: there is no unified theory able to explain all symptoms and the evolution of the disease. There is growing data pointing to metabolic changes and obesity with a central role in IIH pathophysiology. Treatment: most published data on IIH treatment is related to pressure control and protection from visual loss. Acetazolamide and cerebrospinal fluid diversion are the best options available. Optic nerve sheath fenestration might be useful to temporally control the pressure over the optic nerve and thus protect from visual deterioration. Recently, venous sinus stenting has proven to be a safe option in selected cases. Finally, bariatric surgery has proven to effectively control elevated intracranial pressure.

CONCLUSION

IIH is a potential cause of high disability. Early recognition is important, and treatment should be tailored to the needs of each case. There is a lack of research on headache management, which might persist after ICP control.

Association of post-intervention pressure gradient with symptom-free at 6 months in idiopathic intracranial hypertension with venous sinus stenosis treated by stenting

OBJECTIVE

This study aimed to identify the key factors that might affect the clinical outcome of patients with idiopathic intracranial hypertension (IIH) and Venous sinus stenting (VSS).

METHODS

We performed an analysis of a prospectively collected database of patients with IIH and VSS who underwent stenting. The trans-stenotic pressure gradient was measured before and after intervention. In additional, patients' baseline characteristics, procedure details and clinical outcomes at 6-month follow-up (including changes in headache, visual impairment, papilledema, etc.) were recorded. The effects of post-intervention pressure gradient on symptom-free at 6 months were explored using logistic regression analysis, generalized additive model and receiver operator characteristic (ROC) curve.

RESULTS

Of 101 patients included in this study, the median pressure gradient across stenosis decreased from 19 mmHg before intervention to 2 mmHg after intervention. At 6 months, symptom-free was observed in 58 cases (57.4%). Multivariable logistic analysis and generalized additive model showed that post-intervention pressure gradient (increased by 1 mmHg) was independently and linearly correlated with symptom-free (OR = 0.79, 95% CI = 0.67-0.94). Moreover, the post-intervention pressure gradient revealed moderate discrimination with an area under ROC curve of 0.68 (95% CI = 0.57-0.78). Similar associations were observed for the disappearance of headache and papilledema, but not for the visual recovery.

CONCLUSION

The post-intervention pressure gradient may be a valid and reliable predictor of 6-month clinical outcome in patients with IIH and VSS treated by stenting. Nevertheless, external validation with blinded outcome is still needed to confirm its performance before clinical application.

Comparison of microcatheter and pressure wire for venous sinus manometric evaluation of patients with idiopathic intracranial hypertension

BACKGROUND

Venous sinus manometry performed by microcatheter to assess candidacy for venous sinus stenting in patients with idiopathic cranial pressure (IIH) can be tiring, time-consuming and unreliable. Pressure wire is widely used to measure coronary pressure and evaluate coronary stenosis severity, but venous sinus manometry using the pressure guide wire has only been reported in one case, and few studies have examined the accuracy of this approach.

OBJECTIVE

To compare venous manometry performed by microcatheter with by pressure wire under awake setting in patients with IIH.

METHODS

The manometry results of 30 patients with IIH were recorded by Rebar-27 microcatheter and a pressure wire under awake setting. The mean venous pressures (MVPs) and trans-stenosis pressure gradients were obtained and compared between microcatheter and pressure wire. Paired t-test) were used to evaluate the data between the two groups.

RESULTS

MVPs in superior sagittal sinus (SSS) and torcula were slightly higher with microcatheter, though without statistically significant differences (p > 0.05). MVPs in transverse sinus (TS) and sigmoid sinus (SS) were significantly higher with microcatheter (p < 0.05). Trans-stenotic pressure gradient with microcatheter was significantly higher than with pressure wire (p＜0.001).

CONCLUSIONS

Intracranial venous pressure measured with the microcatheter and pressure wire showed a moderate difference. Compared with the traditional microcatheter method，the pressure wire is safe, fast and effective method to identify the patient needing intervention.

A national survey of venous sinus stenting practices for idiopathic intracranial hypertension

Background

Little is currently known about physician opinions and preferences on venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH), practice patterns, or clinical volumes.

Methods

A 19 question online survey was designed and distributed to physician members of the Society of Neurointerventional Surgery (SNIS).

Results

A total of 107 individual survey responses were obtained (14% of SNIS members). The majority of respondents (85%) indicated that they had performed at least one VSS procedure independently during their careers. Mean (SD) and median (range) career case volumes were 20.9 (33.8) and 10.0 (0.0–200.0), respectively. On a 1–10 scale, most respondents reported a high level of interest in treating IIH patients with VSS (median 8), a high level of comfort/expertise in treating IIH patients with VSS (median 9), and that VSS was effective in the long term reduction of symptoms and papilledema in IIH patients (median 8). Fifty-nine per cent of respondents reported increasing VSS volumes compared with previous years. A major complication during a VSS procedure, including two deaths, was reported by 11% of respondents.

Conclusions

This is the first study designed to understand the opinions and practices of neurointerventionists regarding VSS for IIH. Overall physician opinion on VSS was quite positive, supported by increasing procedural volumes reported by most over the past few years. However, only a small percentage of respondents had substantial experience with VSS and major complications were not rare.

New Options (or not) for Treatment of Idiopathic Intracranial Hypertension

PURPOSE OF REVIEW

Idiopathic intracranial hypertension (IIH) is a disorder primarily affecting obese women of childbearing age and, if left untreated, can lead to irreversible vision loss. No consensus exists on the best management strategy for IIH. Weight loss is advocated and few useful medical options exist. There is an unmet need to discover new treatment options for this increasingly prevalent condition. This article reviews the recent advances and research on the treatment of IIH.

RECENT FINDINGS

Venous sinus stenting (VSS) is now performed in many experienced centers, and there is growing interest in bariatric surgery as a treatment modality. Newly approved anti-obesity drugs are showing effectiveness in weight loss, and novel targeted disease-modifying IIH therapies are being explored. Further evaluation of these novel therapeutic strategies as well as studies exploring the use of anti-obesity drugs in IIH is needed. While VSS is gaining popularity due to its efficacy and low complication rate, there is insufficient evidence to support any surgical procedure over another. Bariatric surgery is appealing for patients with non-sight-threatening IIH and needs to be further explored.

Efficacy of dural venous sinus stenting in treating idiopathic intracranial hypertension with acute vision loss

INTRODUCTION

Dural venous sinus stenting (VSS) is an effective, durable treatment for patients with idiopathic intracranial hypertension (IIH) due to underlying venous sinus stenosis. However, the use of venous sinus stenting to treat IIH with acute vision loss has rarely been described.

METHODS

A retrospective chart analysis identified patients who received VSS for fulminant IIH, defined as acute (< 8 weeks) visual field loss to within the central 5° and/or a decrease in visual acuity to less than or equal to 20/50 in either eye in the presence of papilledema.

RESULTS

Ten patients were identified with average patient age of 31.0 years, and all except one were female. Mean body mass index was 41.2 kg/m². All patients presented with vision loss and some with headache and tinnitus. The average trans-stenotic gradient pre-stenting was 28.7 mmHg (range 9-62 mmHg). All patients had diminished or resolved venous gradients immediately following the procedure. At mean follow-up of 60.5 weeks, 100% had improvements in papilledema, 80.0% had subjective vision improvement, 55.6% had headache improvement and 87.5% had tinnitus improvement. 90.0% had stable or improved visual acuity in both eyes with a mean post-stenting Snellen acuity of 20/30 and an average gain of 3 lines Snellen acuity post-stenting (95% confidence intervals 0.1185-0.4286, p = 0.0018). Two patients (20.0%) required further surgical treatment (cerebrospinal shunting and/or stenting) after their first stenting procedure.

CONCLUSIONS

This series suggests that VSS is feasible in patients presenting with IIH and acute vision loss with a fairly low complication rate and satisfactory clinical outcomes.

A proposed framework for cerebral venous congestion

BACKGROUND

While venous congestion in the peripheral vasculature has been described and accepted, intracranial venous congestion remains poorly understood. The characteristics, pathophysiology, and management of cerebral venous stasis, venous hypertension and venous congestion remain controversial, and a unifying conceptual schema is absent. The cerebral venous and lymphatic systems are part of a complex and dynamic interaction between the intracranial compartments, with interplay between the parenchyma, veins, arteries, cerebrospinal fluid, and recently characterized lymphatic-like systems in the brain. Each component contributes towards intracranial pressure, occupying space within the fixed calvarial volume. This article proposes a framework to consider conditions resulting in brain and neck venous congestion, and seeks to expedite further study of cerebral venous diagnoses, mechanisms, symptomatology, and treatments.

METHODS

A multi-institution retrospective review was performed to identify unique patient cases, complemented with a published case series to assess a spectrum of disease states with components of venous congestion affecting the brain. These diseases were organized according to anatomical location and purported mechanisms. Outcomes of treatments were also analyzed. Illustrative cases were identified in the venous treatment databases of the authors.

CONCLUSION

This framework is the first clinically structured description of venous pathologies resulting in intracranial venous and cerebrospinal fluid hypertension. Our proposed system highlights unique clinical symptoms and features critical for appropriate diagnostic work-up and potential treatment. This novel schema allows clinicians effectively to approach cases of intracranial hypertension secondary to venous etiologies, and furthermore provides a framework by which researchers can better understand this developing area of cerebrovascular disease.

Neuro-ophthalmological evaluation including optical coherence tomography surrounding venous sinus stenting in idiopathic intracranial hypertension with papilledema: a case series

Venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH) has been demonstrated to achieve significant symptom improvement while harboring a low periinterventional morbidity profile. Comprehensive neuro-ophthalmological monitoring represents a cornerstone of disease monitoring. The value of optical coherence tomography (OCT) requires further exploration. Patients with IIH and papilledema who underwent VSS between 04/2018 and 02/2021 were retrospectively reviewed. Clinical and radiological were analyzed. Neuro-ophthalmological data included visual acuity, visual fields, fundoscopy categorized via Frisén scale, and OCT obtained retinal nerve fiber layer (RNFL) thickness were analyzed. Of 39 IIH patients who underwent cerebral angiography with transverse-sigmoid sinus pressure evaluation, 18 patients with IIH and papilledema underwent 21 transverse-sigmoid sinus stenting (TSST) procedures. After TSST, manometry showed a significant reduction of maximum transverse sinus pressures and trans-stenotic gradient pressures (p = 0.005 and p < 0.001, respectively). Chronic headaches, visual disturbance resolved and pulsatile tinnitus improved significantly. Visual fields remained similar, while papilledema Frisén scales and visual acuity significantly improved. The OCT calculated RNFL thickness significantly decreased in all patients. Stratification according to a minimal-low degree (Frisén 1-2) and moderate-marked degree (Frisén 3-4) papilledema demonstrated a significant reduction of RNFL thickness in both groups. Venous sinus stenting provides favorable clinical and neuro-ophthalmological outcomes. This study demonstrates that neuro-ophthalmologic testing augmented with OCT evaluation provides objective data that can be used as a biomarker for treatment success for managing patients with different extents of papilledema and may inform patient management.

Evolution of MRI Findings in Patients with Idiopathic Intracranial Hypertension after Venous Sinus Stenting

BACKGROUND AND PURPOSE

The correlation between imaging findings and clinical status in patients with idiopathic intracranial hypertension is unclear. We aimed to examine the evolution of idiopathic intracranial hypertension-related MR imaging findings in patients treated with venous sinus stent placement.

MATERIALS AND METHODS

Thirteen patients with idiopathic intracranial hypertension (median age, 26.9 years) were assessed for changes in the CSF opening pressure, transstenotic pressure gradient, and symptoms after venous sinus stent placement. Optic nerve sheath diameter, posterior globe flattening and/or optic nerve protrusion, empty sella, the Meckel cave, tonsillar ectopia, the ventricles, the occipital emissary vein, and subcutaneous fat were evaluated on MR imaging before and 6 months after venous sinus stent placement. Data are expressed as percentages, medians, or correlation coefficients (r) with P values.

RESULTS

Although all patients showed significant reductions of the CSF opening pressure (31 versus 21 cm H₂O; P = .005) and transstenotic pressure gradient (22.5 versus 1.5 mm Hg; P = .002) and substantial improvement of clinical symptoms 6 months after venous sinus stent placement, a concomitant reduction was observed only for posterior globe involvement (61.5% versus 15.4%; P = .001), optic nerve sheath diameter (6.8  versus 6.1 mm; P < .001), and subcutaneous neck fat (8.9  versus 7.4 mm; P = .001). Strong correlations were observed between decreasing optic nerve sheath diameters and improving nausea/emesis (right optic nerve sheath diameter, r =  0.592, P = .033; left optic nerve sheath diameter, r = 0.718, P = .006), improvement of posterior globe involvement and decreasing papilledema (r = 0.775, P = .003), and decreasing occipital emissary vein diameter and decreasing headache frequency (r = 0.74, P = .035). Decreasing transstenotic pressure gradient at 6 months strongly correlated with decreasing empty sella (r = 0.625, P = .022) and regressing cerebellar ectopia (r = 0.662, P = .019).

CONCLUSIONS

Most imaging findings persist long after normalization of intracranial pressure and clinical improvement. However, MR imaging findings related to the optic nerve may reflect treatment success.

The Case of a Patient with Idiopathic Intracranial Hypertension Who Required Additional Stenting for Stent-Adjacent Stenosis

Objective

We report the case of a patient with recurred idiopathic intracranial hypertension (IIH) with transverse sinus (TS) stenosis after initial stenting, which was treated with additional stent placed in tandem to the secondarily occurred stent-adjacent stenosis (SAS).

Case Presentation

A 41-year-old woman complained of reduced visual acuity and blurred vision, and presented with papilledema. Lumbar puncture revealed an opening pressure of 36 cmH₂O. MRI revealed no space-occupying lesions, and the patient was diagnosed with IIH based on the modified Dandy criteria. MR venography revealed stenosis in the right and hypoplastic left TS. The patient complained of headache and neck pain after each lumbar puncture for examination. Venous sinus stenting (VSS) was performed in the right TS. One month after stenting, follow-up angiography revealed stenosis in the remaining parts of TS. Five months after stenting, IIH recurred, and SAS was detected on angiography. An additional stenting procedure was performed. Three months after the second treatment, her symptoms disappeared and cerebrospinal fluid pressure was normalized.

Conclusion

Patients with post-VSS recurrent IIH may develop restenosis in the remaining parts of TS at variable progression speeds. In this case, angiography revealed gradually advancing stenosis that seemed to form SAS at the time of recurrence. If the initial VSS is effective for IIH, SAS can also be treated effectively and less invasively with a second stent placement covering the entire TS length.

Endovascular catheter manometry reliability: a benchtop validation study

OBJECTIVE

Catheter manometry is used frequently in neuroendovascular surgery for assessing cerebrovascular pathology. The accuracy of pressure data with different catheter setups requires further validation.

METHODS

In a silicone human vascular model with a pulsatile pump, pressure measurements were taken through multiple arrangements of 2 guide catheters and 6 microcatheters. The systolic pressure, diastolic pressure, mean pressure, pulse pressure, and area under the curve of the waveform were recorded through catheters with controls at arterial blood pressure ranges. Linear regression modeling was performed, correlating transduction area and relative pulse pressure. Thresholds for acceptable accuracy were ≥ 90%.

RESULTS

Mean pressure demonstrated < 4% variation between all 24 catheter setups and respective controls. A strong linear correlation (r2 = 0.843, p < 0.0005) between microcatheter transduction area and relative pulse pressure with a threshold of 0.50 mm2 was seen (i.e., 0.031-inch inner diameter [ID]). For guide catheters with indwelling microcatheters, there was also a strong linear correlation (r2 = 0.840, p < 0.0005) of transduction area to pulse pressure. The guide catheters with obstructing microcatheters required a transduction area over fourfold higher compared with unobstructed microcatheters (2.21 mm2 vs 0.50 mm2).

CONCLUSIONS

Mean pressure measurements are accurate through microcatheters as small as 0.013-inch ID. Pulse pressure and waveform morphology may require a microcatheter ≥ 0.031-inch ID to achieve 90% accuracy, although the 0.027-inch ID microcatheter reached 85% accuracy. A 0.070-inch guide catheter with a microcatheter ≤ 0.042-inch outer diameter (e.g., Marksman 0.027-inch ID or smaller) allows accurate transduction of pulse pressure. Further validation of these benchtop findings is necessary before application in a clinical setting.

Intracranial venous sinus stenting for the treatment of lateral sinus stenoses: An analysis of 200 patients

PURPOSE

The purpose of this study was to analyze the long-term efficacy and safety of intracranial venous sinus stenting in a large cohort of patients with any type of presentation of primary lateral venous sinus stenosis (VSS).

MATERIALS AND METHODS

A retrospective cohort study was performed including patients treated by venous sinus stenting for symptomatic VSS from 2012 to 2019. Successful primary resolution of symptoms without adjunctive treatment or recurrence, and complications after stenting were analyzed at the last follow-up time point.

RESULTS

Two-hundred patients were included. There were 14 men and 186 women with a mean age of 39±14 (SD) years (age range: 13-75 years). Presenting symptoms included venous pulsatile tinnitus in 168 patients (168/200; 84%), idiopathic intracranial hypertension in 100 patients (100/200; 50%) and/or spontaneous cerebrospinal fluid leak in 35 patients (35/200; 17%). The overall rate of successful primary resolution of any typical presenting symptoms was 79% (95% CI: 73-85%). This rate ranged from 74% to 93% depending on the symptom with no significant difference between patients with and those without idiopathic intracranial hypertension (P=0.08). Recurrence rate was 10% (95% CI: 6-14%). No death or permanent morbidity were observed during a median follow-up of 2.2 years (Q1, Q3: 1.4, 3.3; range: 1-7.7 years).

CONCLUSION

Our study shows that venous sinus stenting has a low morbidity and high success rate at long-term follow-up for the treatment of idiopathic intracranial hypertension, venous pulsatile tinnitus or spontaneous cerebrospinal fluid leak associated with VSS. The excellent safety suggests considering this treatment as first-line treatment when medical management is ineffective or poorly tolerated.

Intracranial Venous Hypertension and Venous Sinus Stenting in the Modern Management of Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) is a debilitating condition that has traditionally been difficult to treat. In recent years, there has been increasing focus on the role of intracranial venous hypertension in the pathophysiology of IIH. Based on increased understanding of this pathophysiology, venous sinus stenting (VSS) has emerged as a safe and reliable treatment for a certain population of patients with IIH. Stratifying patients with IIH based on the status of their venous outflow can provide insight into which patients may enjoy reduction in their symptoms after VSS and provides information regarding why some patients may have symptom recurrence. The traditional view of IIH as a disease due to obesity in young women has been cast into doubt as the understanding of the role of intracranial venous hypertension has improved.

Casper Versus Precise Stent for the Treatment of Patients with Idiopathic Intracranial Hypertension

Purpose

We hypothesized that due to its specific characteristics, the Casper^TM RX carotid stent (CP) might be particularly suitable for venous sinus stenting (VSS) in patients with idiopathic intracranial hypertension (IIH). To test this theory, we compared it to the commonly used Precise Pro RX^TM stent (PP).

Methods

A total of 15 patients with IIH (median age 28.7 years) were reviewed retrospectively. Technical aspects as well as peri- and postinterventional complication rates were examined in patients treated with CP (n = 10) and the PP (n = 5). Improvements in cerebrospinal fluid opening pressure (CSF OP), transstenotic pressure gradient (TSPG) and clinical symptoms were also assessed.

Results

Stent delivery was easier and more successful with the CP than the PP (difficult/failed stent delivery 0.0% versus 57.1%) and consequently achieved with less attempts (≥ 2: 0.0% versus 40.0%). No severe peri- or postinterventional complications or instances of in-stent thrombosis and/or stenosis were observed during follow-up. Improvement of CSF OP and TSPG immediately after VSS as well as at 6‑month follow-up was comparable between the CP and PP group. Both groups showed substantial and similar decreases in intensity and frequency of headache. Almost all patients with other IIH-related symptoms showed either improvement or complete resolution of those symptoms after VSS. All patients who were available for interview (n = 12/15) reported a substantial improvement in quality of life.

Conclusion

VSS using the CP seems to be safe and effective. The CP may reduce the risk of difficult or failed stent delivery in patients with challenging intracranial venous anatomy.

Supplementary Information

The online version of this article (10.1007/s00062-021-01024-2) contains supplementary material, which is available to authorized users.

Dural venous sinus stenting in the treatment of idiopathic intracranial hypertension: A systematic review and critique of literature

Idiopathic intracranial hypertension (IIH) is increased intracranial pressure without a known cause. Dural venous sinus stenting (DVSS) is a relatively new intervention for treatment of IIH refractory to medical therapy and lifestyle modifications. In this review, we outline various hypotheses of IIH pathogenesis and describe the role of venous sinus stenosis and the technical details of DVSS. We also present a summary and critique of the available evidence describing the outcomes of DVSS in IIH and review the evidence-based guidelines for this procedure. We conclude that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and postprocedure ophthalmological data. Thus, there is not enough available evidence to conclude whether DVSS is an effective procedure for treatment of IIH. We also present the most commonly used indications for DVSS as described in the literature and stress the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.

Major complications of dural venous sinus stenting for idiopathic intracranial hypertension: case series and management considerations

BACKGROUND

Venous sinus stenting (VSS) is a safe, effective, and increasingly popular treatment option for selected patients with idiopathic intracranial hypertension (IIH). Serious complications associated with VSS are rarely reported.

METHODS

Serious complications after VSS were identified retrospectively from multicenter databases. The cases are presented and management strategies are discussed.

RESULTS

Six major acute and chronic complications after VSS were selected from a total of 811 VSS procedures and 1466 venograms for IIH. These included an acute subdural hematoma from venous extravasation, cases of both intraprocedural and delayed stent thrombosis, an ultimately fatal cerebellar hemorrhage resulting in acute obstructive hydrocephalus, venous microcatheter perforation during venography and manometry, and a patient who developed subarachnoid hemorrhage and subdural hematoma after cerebellar cortical vein perforation. The six cases are reviewed and learning points regarding complication avoidance and management are presented.

CONCLUSION

We report on six rare, major complications after VSS for IIH. Familiarity with these potential complications and appropriate timely management may allow for good clinical outcomes.

Venous sinus stenting for intractable pulsatile tinnitus: A review of indications and outcomes

Background:

Pulsatile tinnitus presents as a unique variation of tinnitus in which a conscious perception of the heartbeat is localized to the ears in either unilateral or bilateral fashion. The sensation is typically caused by an increase in turbulent blood flow in the affected ear, in most cases, due to a structural abnormality of the venous sinuses – the most common of which being stenosis. Herein, we discuss the etiology of pulsatile tinnitus followed by indications for treatment of various pathologies which have been successfully treated with venous sinus stenting and have led to resolution of auditory symptoms.

Methods:

The authors queried PubMed database using combinations of the keywords “venous sinus stenting,” “endovascular treatment,” and “pulsatile tinnitus” to identify relevant studies published in English after 2001 and before December 1, 2020 and verified selected.

Results:

Our results corroborate those published in prior reviews reporting a high rate of pulsatile tinnitus resolution with venous sinus stenting.

Conclusion:

The success of venous sinus stenting is clinically relevant as an effective treatment option for patients suffering from pulsatile tinnitus. Future applications and studies are needed and are currently being developed to further demonstrate the effectiveness of stents in the treatment of pulsatile tinnitus.

Correlation between intracranial pressure and venous sinus pressures in patients undergoing cerebral venography and manometry

BACKGROUND

The pathophysiology of idiopathic intracranial hypertension (IIH) is complex but is directly related to cerebral venous hypertension. Few studies have simultaneously recorded venous sinus pressures and lumbar puncture (LP) opening pressure (OP) to understand the relationship between these factors without temporal confounding.

METHODS

A retrospective review was performed of patients with a known or suspected diagnosis of IIH who underwent cerebral venography with manometry followed immediately by LP.

RESULTS

47 patients aged 16-68 years met inclusion criteria. 91.5% were female. Mean body mass index (BMI) was 33.3 kg/m². Of the included patients, median OP was 21 cm H₂O (IQR (15.5, 26.5)). Mean (SD) recorded superior sagittal sinus (SSS) and torcular pressures were 25.5 (16.5) mm Hg and 23.8 (16.6) mm Hg, respectively. Twenty patients (42.6%) were discovered to have a trans-stenosis gradient of 8 mm Hg or greater. Transverse sinus, torcula, and SSS pressures were all significantly predicted by OP. On regression analysis, torcular pressures were best predicted by OP of the three measured sites. For 17 patients with OP <20 cm H₂O (36.2%), mean (SD) SSS and torcular pressures were 13.5 (4.2) mm Hg and 15.4 (6.7) mm Hg, respectively, suggesting that normally SSS pressures should measure <18 mm Hg (80th percentile) in non-pathologic conditions.

CONCLUSIONS

This is the first study to correlate venous sinus pressures and OP in patients with IIH with LP performed directly after manometry. In 47 patients, LP OP significantly predicted transverse sinus, torcula, and SSS pressures. Torcular pressures (mm Hg) were most accurately predicted by OP (cm H₂O) in a nearly one-to-one relationship.

Pathogenesis and Management in Cerebrovenous Outflow Disorders

In keeping with its status as one of the major causes of disability and mortality worldwide, brain damage induced by cerebral arterial disease has been the subject of several decades of scientific investigation, which has resulted in a vastly improved understanding of its pathogenesis. Brain injury mediated by venous etiologies, however, such as cerebral, jugular, and vertebral venous outflow disturbance, have been largely ignored by clinicians. Unfortunately, this inattention is not proportional to the severity of cerebral venous diseases, as the impact they exact on the quality of life of affected patients may be no less than that of arterial diseases. This is evident in disease sequelae such as cerebral venous thrombosis (CVT)-mediated visual impairment, epilepsy, and intracranial hypertension; and the long-term unbearable head noise, tinnitus, headache, dizziness, sleeping disorder, and even severe intracranial hypertension induced by non-thrombotic cerebral venous sinus (CVS) stenosis and/or internal jugular venous (IJV) stenosis. In addition, the vertebral venous system (VVS), a large volume, valveless vascular network that stretches from the brain to the pelvis, provides a conduit for diffuse transmission of tumors, infections, or emboli, with potentially devastating clinical consequences. Moreover, the lack of specific features and focal neurologic signs seen with arterial etiologies render cerebral venous disease prone to both to misdiagnoses and missed diagnoses. It is therefore imperative that awareness be raised, and that as comprehensive an understanding as possible of these issues be cultivated. In this review, we attempt to facilitate these goals by systematically summarizing recent advances in the diagnosis and treatment of these entities, including CVT, CVS stenosis, and IJV stenosis, with the aim of providing a valid, practical reference for clinicians.

Angiographic cerebral venous sinus calibers and drainage patterns in patients with normal intracranial pressure and idiopathic intracranial hypertension

BACKGROUND

Normative venous sinus diameters are not well established. This study seeks to compare two-dimensional digital subtraction cerebral angiographic (DSA) venous sinus calibers for patients with normal intracranial pressure (ICP) and with idiopathic intracranial hypertension (IIH).

METHODS

Patients who underwent diagnostic cerebral angiography from 2016 to 2020 were retrospectively identified. Two independent reviewers measured venous sinus calibers from anteroposterior (AP) and lateral carotid injection delayed venous phase in patients from two groups (group 1: patients with normal ICP; group 2: patients with IIH) after receiving training in a standardized measurement protocol, with measurements obtained from the superior sagittal sinus (SSS) through the sigmoid sinuses (SS).

RESULTS

97 patients from group 1 and 30 patients from group 2 were included. Interrater reliability was greater than 0.75 for all measured sites. Both groups had similar anatomical subtypes with most being right transverse sinus (TS) dominant or codominant. In group 1, men had significantly larger SSS on lateral view (p<0.001) and dominant TS calibers on AP view (p=0.02) compared with women. Both dominant TS measurements and SSS measurements (lateral plane) were significantly smaller among group 2 compared with group 1 (p<0.001 and 0.02, respectively). Patients with IIH had significantly larger dominant SS measurements (p=0.01). Bifid SSS anatomy was present in 9% of patients with mean caudal width 31 mm (range 19-49 mm).

CONCLUSIONS

This study is the first to provide two-dimensional DSA dural venous sinus calibers in patients with and without IIH and to compare anatomical drainage types and calibers among groups.

Predicting the need for retreatment in venous sinus stenting for idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension is a disease of raised intra-cranial pressure of unknown etiology. Lateral cerebral venous sinus stenosis (VSS) has been increasingly reported in these patients, and stenting has emerged as an alternative treatment for medically refractory symptoms. Treatment efficacy on meta-analysis appears promising, but identifying which patients are likely to benefit most, and which are likely to require repeat procedures, is currently unclear.

METHODS

We retrospectively reviewed a prospectively collected database of 79 patients treated with venous sinus stenting at a single academic center with minimum follow-up of 18 months. We extracted baseline clinical data, as well as manometry at lumbar puncture and during angiography, and used logistic regression to identify parameters that could predict stent failure.

RESULTS

Retreatment rate after successful VSS was 13.9%. Lumbar puncture opening pressure (OP) was shown to significantly predict treatment failure (ß=0.06; OR=1.064 (1.003-1.135); P=0.039). This effect remained significant when age, sex and body mass index were added to the model (ß=0.06; OR=1.066 (1.002-1.140); P=0.043). OP was correlated with venous sinus manometry readings in the superior sagittal and transverse sinus pre-stent placement, as well trans-stenotic gradient (P<0.001).

CONCLUSIONS

Higher lumbar puncture OP was associated with an increased risk of stent failure in transverse sinus stenting for idiopathic intracranial hypertension, although the performance of this model as a linear discriminator was poor. Further studies are required to better assess which patients are at greatest risk of treatment failure.

Dural venous sinus stenting for treatment of pediatric idiopathic intracranial hypertension

BACKGROUND

Dural venous sinus stenting (VSS) is an effective treatment for idiopathic intracranial hypertension (IIH) in adult patients. There are no published series to date evaluating safety and efficacy of VSS in pediatric patients.

OBJECTIVE

To report on procedural device selection and technique as well as safety and efficacy of VSS for pediatric patients with medically refractory IIH due to underlying venous sinus stenosis.

METHODS

A multi-institutional retrospective case series identified patients with medically refractory IIH aged less than 18 years who underwent VSS.

RESULTS

14 patients were identified at four participating centers. Patient ages ranged from 10 to 17 years, and 10 patients (71.4%) were female. Mean body mass index was 25.7 kg/m² (range 15.8-34.6 kg/m²). Stenting was performed under general endotracheal anesthesia in all except two patients. The average trans-stenotic gradient during diagnostic venography was 10.6 mm Hg. Patients had stents placed in the superior sagittal sinus, transverse sinus, sigmoid sinus, occipital sinus, and a combination. Average follow-up was 1.7 years after stenting. Six patients out of 10 (60%) had reduced medication dosing, 12 of 14 patients (85.7%) had improvements in headaches, two patients (100%) with pre-stent tinnitus had resolution of symptoms, and four (80%) of five patients with papilledema had improvement on follow-up ophthalmological examinations. Two patients (14.3%) developed postprocedural groin hematomas, one patient (7.1%) developed a groin pseudoaneurysm, and one patient (7.1%) had postprocedural groin bleeding. No other procedural complications occurred. Four patients (28.6%) required further surgical treatment (cerebrospinal shunting and/or stenting) after their first stenting procedure.

CONCLUSIONS

This series suggests that VSS is feasible in a pediatric population with IIH and has a low complication rate and good clinical outcomes.

Quality of life, need for retreatment, and the re-equilibration phenomenon after venous sinus stenting for idiopathic intracranial hypertension

BACKGROUND

Long term failure rates after venous sinus stenting (VSS) for idiopathic intracranial hypertension (IIH) are poorly understood.

METHODS

Retrospective analysis was performed on a prospectively-maintained single center database to identify patients with medically refractory IIH who underwent VSS. Patients with persistent or severe recurrent symptoms after VSS undergo lumbar puncture (LP), therefore LP serves as a marker for treatment failure.

RESULTS

81 patients underwent VSS with a mean follow-up of 10 months; 44 (54.3%) patients underwent LP after VSS due to persistent or recurrent symptoms at a mean of 12 months (median 7, range 2-43). There was a mean decrease in opening pressure (OP) on LP from pre- to post-VSS of 9.1 cm H₂O (median 9.5). Overall, a total of 21 (25.9%) patients underwent further surgical intervention following VSS, including five who underwent repeat VSS (6.2% of total) and 18 who underwent cerebrospinal fluid shunting (22.2% of total). There was a non-significant (p=0.18) but overall increase in quality of life scores from pre-stenting (61.2) to last follow-up (71.2), and a significant decrease in Headache Impact Test-6 (HIT-6) scores (p=0.03) with mean pre-stenting and last follow-up scores of 62.7 and 55.8, respectively.

CONCLUSIONS

VSS is an effective treatment for venous sinus stenosis in IIH; however, this study found higher rates of symptomatic recurrence and need for further surgical intervention (26%) than previously reported in the literature. Recurrence of symptoms occurred at a median of 7 months, even though OP remained lower at follow-up LP, suggestive of a re-equilibration phenomenon.

Perioperative mannitol intensive use may avoid the early complication of cerebral venous sinus stenting

Background

Cerebral venous sinus (CVS) stenting has been widely applied for correcting CVS stenosis. However, there are still some potential complications. The purpose of this study is to investigate the impact of perioperative management on avoiding complications of CVS stenting.

Methods

Patients confirmed as CVS stenosis were enrolled from January 2014 through November 2019. All CVS stenosis were corrected by stenting when the trans-stenotic mean pressure gradient (MPG) was up to or over 8 mmHg. Patients were divided into perioperative management group and control group. Patients in the former group underwent transiently mannitol 250 mL intravenous infusion immediately prior to stenting besides routine ICP control. While patients in control group underwent the same routine treatment as in the perioperative management group. The clinical symptoms, intracranial pressure (ICP), and MPG of the patients were compared before and after stenting. In addition, the complications between the two groups were compared.

Results

A total of 81 eligible patients were finally enrolled in this study, including 64 females and 17 males, mean aged 45.35±13.83 years. After stenting, the stenotic CVS restored normal blood flow and MPG decreased significantly [10.0 (8.0–15.0) vs. 0.0 (0.0–0.7) mmHg, P<0.001]. Headache, tinnitus, visual impairment, visual loss, Frisén papilledema grade (FPG), and ICP were ameliorated immediately (P<0.001) in the majority of patients in the two groups. However, the incidence of intracranial hemorrhage was higher in control group (11.4% vs. 0.0%, P=0.031).

Conclusions

A transiently strict preoperative ICP control by mannitol may inhibit CVS stenting-related hemorrhage, which makes the stenting safer and more effective on correcting the CVS stenosis.